Are superflares on solar analogues caused by extrasolar planets?

被引:95
作者
Rubenstein, EP [1 ]
Schaefer, BE [1 ]
机构
[1] Yale Univ, Dept Astron, New Haven, CT 06520 USA
基金
美国国家科学基金会;
关键词
planetary systems; magnetic fields; stars : flare; stars : individual (kappa Ceti; pi(1) Ursae Majoris); stars : late-type; stars : magnetic fields;
D O I
10.1086/308326
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Stellar hares with 10(2)-10(7) times more energy than the largest solar hare have recently been detected from nine normal F and G main-sequence stars by Schaefer, King, and Deliyannis. These superflares have durations of hours to days and are visible from at least X-ray to optical frequencies. The absence of world-spanning aurorae in historical records and of anomalous extinctions in the geological record indicates that our Sun likely does not suffer superflares. In seeking to explain this new phenomenon, we are struck by its similarity to large stellar flares on RS Canum Venaticorum binary systems, which are caused by magnetic reconnection events associated with the tangling of magnetic fields between the two stars. The superflare stars are certainly not of this class, although we propose a similar flare mechanism. That is, superflares are caused by magnetic reconnection between fields of the primary star and a close-in Jovian planet. Thus, by invoking only known planetary properties and reconnection scenarios, we can explain the energies, durations, and spectra of superflares as well as explain why our Sun does not have such events.
引用
收藏
页码:1031 / 1033
页数:3
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